== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 12:39:03 (1783355943)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       23320     1247984   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       17544     1253760   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25996     3581024   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       19560     3587460   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45556     7168484   1%  /mnt/lustre